In the present note we show asynchronous exponential growth for important age and size-structured population models. 2000 MSC: 92D25, 47D06, 35B35

In this paper we propose a macro-dynamic age-structured set-up for the analysis of epidemics/economic dynamics in continuous time. The resulting optimal control problem is reformulated an infinite dimensional Hilbert space framework where perform basic steps dynamic programming approach. Our main result verification theorem which allows to guess feedback form strategies. This will be departure ...

Classical age-structured mass-action models such as the McKendrick-von Foerster equation have been extensively studied but are unable to describe stochastic fluctuations or population-size-dependent birth and death rates. Stochastic theories that treat semi-Markov age-dependent processes using, e.g., the Bellman-Harris equation do not resolve a population's age structure and are unable to quant...

this study compared the use of five different models to describe the growth from birth to 20 weeks of age of kids from both genders of nondescript goats. fifty nine (59) nondescript kids were weighed weekly at the university of maiduguri livestock teaching and research farm, nigeria and the live weights were modeled. biologically relevant variables were estimated for each kid from the logistic,...

We prove analytically the existence of chaotic dynamics in some classical discrete-time age-structured population models. Our approach allows us to estimate the sensitive dependence on the initial conditions, regions of initial data with chaotic behavior, and explicit ranges of parameters for which the considered models display chaos. These properties have important implications for evaluating ...

Our systematic formulation of nonlinear population models is based on the notion of the environmental condition. The defining property of the environmental condition is that individuals are independent of one another (and hence equations are linear) when this condition is prescribed (in principle as an arbitrary function of time, but when focussing on steady states we shall restrict to constant...